The art of composition

Form a stepped garden bed by mixing plants of three or four different heights to give a border effect, positioning low-growing annuals at the front and taller plants at the back.

Arrange the plants in a series of steps, working from low plants under 20cm at the front of the bed to tall plants over 1m high at the back. The seed packets and plant labels display the plant height.

Shrubs make a great backdrop for a garden bed, as do climbers, such as jasmine and clematis, and tall perennials like cannas.

Climbers have the advantage of occupying little ground space, which makes them useful if your bed is narrow or your garden is small.

For a natural look, establish your flowerbed as an extension of an existing feature in your garden.

Merge it into another group of plants such as a bed of shrubs or a hedge. Or you can back it onto hard landscaping like a pathway, low wall, pergola, patio or steps.

Creating a layered effect gives a flowerbed depth

Get off to a good start

Although it is tempting, do not buy young stalky plants in flower. Choose healthy, compact plants with vibrant green leaves and well-branched stems.

The base of the stem should be strongly attached to the root mass, not loose, and the rootball should be damp to the touch. Reject plants with either dry or saturated potting mix.

Care for new plants

Watering the plants regularly is vital, especially immediately after planting and during hot weather.

To avoid disturbing young plants, use a watering can fitted with a fine rose and hold it high above the plants.

If watering with a hose, use a nozzle attachment and point it upwards over the plants so they’re not damaged by too much pressure.

Hoe the ground regularly to get rid of weeds that will compete with your plants. Mulching well will also help reduce weeds.

Pinch out for strength

Encourage the young plants to develop into sturdy, bushy specimens by pinching out the tips of shoots.

Grasp the tip between your thumb and index finger, just above a leaf or pair of leaves.

This light pruning slightly delays flowering, but it will be more abundant when it starts. Pinch out heliotrope, cosmos, and petunia regularly.

The fragile stems of campanula, aster and rudbeckia are vulnerable in wind. Pinching out the tips will restrict their height and help them to remain upright.

Protect from the sun

As summer warms up, certain plants will suffer if they are still positioned in full sun.

To give plants spring sun and summer shade, plant ferns, fuchsias, hostas and euphorbias under the shelter of small deciduous trees such as crepe myrtle, frangipani, Japanese maple or tulip tree.

Shade lovers

These perennials won’t just survive in full shade, they’ll thrive and have gorgeous blooms and foliage.

Columbine flower. Image: Thinkstock

Sweet woodruff. Image: Thinkstock

Bleeding heart. Image: Thinkstock

Coral bells. Image: Alamy

Foxglove. Image: Thinkstock

Astilbe. Image: Alamy

How to create a stepped flowerbed

Mix three or four plants of different heights to give a stepped effect, using low-growing annuals up to 20cm at the front of the bed and gradually working up to tall plants 1m or over at the back of the bed.

First row (10-20cm)

Gazania. Image: Thinkstock

Lobelia. Image: Thinkstock

Sweet Alyssum. Image: Thinkstock

Portulaca. Image: Thinkstock

Second row (20-50cm)

Ageratum. Image: Thinkstock

Dusty Miller. Image: Alamy

New Guinea Impatiens. Image: Thinkstock

Petunia. Image: Thinkstock

Third row (50cm-1m)

Cornflower. Image: Thinkstock

Delphinium. Image: Thinkstock

Marigold. Image: Thinkstock

Snapdragon. Image: Thinkstock

Fourth row (over 1m)

Amaranthus. Image: Thinkstock

Cleome. Image: Thinkstock

Sunflower. Image: Thinkstock

Hollyhock. Image: Thinkstock

Collecting seeds

Gather seeds before deadheading spent flowers and store them ready to replant next year.

PUT A PAPER BAG over the flowers that have finished blooming, then secure it around the stem of the plant with string. When the stems have dried out, cut just below the tie, turn the bag upside down and shake the plant so the seeds fall into it.

MAKE A CONE out of newspaper to gather seeds from dried flowerheads. Roll up two sheets from a large newspaper to make a cone with a wide opening at the top.

Fold and secure the cone at the base to stop the seeds escaping, shake the seed-laden plant over the cone, then fold over the newspaper at the top.

USE AN OLD SIEVE to collect small seeds from plants like snapdragons and petunias. Put the ripe, dry flowerheads into an old kitchen sieve, rub gently over the mesh and the seeds will fall through.

AIR-DRY SEEDS thoroughly on newspaper to reduce the risk of mould, before storing them.

STORE THE SEEDS in old pill bottles, which are ideal as the drying agent in the cap protects them from damp. Or keep them in film canisters or in envelopes or paper bags, then peg them to a line in a dry, well-aired space. Collect the bags of absorbent silica gel that come with electrical equipment or in vitamin bottles, then drop them into the containers where you store the seeds.

To keep off weevils and rodents, add a mothball to the storage containers.

TIP Never store seeds in a plastic bag, as it won’t allow air through and the seeds will rot.

A paper bag is an easy way to save your seeds for replanting. Image: Alamy